TOI-3896 b
Astrophysical Synthesis & Habitability Characterization
TOI-3896 b is a confirmed sub-neptune exoplanet orbiting the star TOI-3896, located approximately 592.5 light-years (181.65 parsecs) from the Solar System. First announced in 2026 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.149% across the stellar disk), this world measures 3.149 Earth radii (0.28 Jupiter radii) and has a measured mass of 10.1 Earth masses. Combining its mass and radius yields a mean bulk density of 1.78 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.02 g⊕ (10 m/s²), and an escape velocity of 20 km/s.
In its orbital architecture around TOI-3896, TOI-3896 b completes one full revolution every 4.377 Earth days.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 966 K (+693°C / +1279°F) and receiving 144.99 S⊕ (~197,329 W/m²), TOI-3896 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star TOI-3896 is classified as a stellar host with an effective photospheric temperature of 5,111 K, a radius of 0.7478 R☉, a mass of 0.86 M☉, an estimated bolometric luminosity of 0.342 L☉. From Earth, TOI-3896 shines at apparent V-band magnitude 12.43 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | TOI-3896 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,111 K |
| Stellar Radius | 0.7478 R☉ |
| Stellar Mass | 0.8600 M☉ |
| Bolometric Luminosity | 0.342 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 12.430 · G: 12.233 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 4.377 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 87.7484° |
| Mean Bulk Density | 1.78 g/cm³ (20 km/s vesc) |
| Insolation Flux | 144.9880 S⊕ (~197,329 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 592.500 LY (181.653 pc) |